Pyridobenzodiazepinones

ABSTRACT

1,2-Dihydro-8-phenyl-3H-pyrido(3,2,1-jk)(1,4)benzodiazepin5(6H)-ones, processes for preparing the same and intermediates prepared by said processes. The novel compounds of this invention exhibit tranquilizing and anticonvulsant activity in animals.

United States Patent 1191 Hester, Jr.

[ Jan. 30, 1973 [54] PYRIDOBENZODIAZEPINONES [75] Inventor: Jackson B. Hester, Jr., Portage,

[21] App]. No.: 873,719

[52] U.S. Cl ..260/239.3 T, 260/288 R, 260/289 R,

[51] Int. Cl. ..C07d 53/06 [58] Field of Search ..260/239l3 T [56] References Cited OTHER PUBLICATIONS Harter et al., Acta Chem. Scand. Vol. 22, No. 10, (1968) pages 3,332-3,333.

Primary Examiner.lohn D. Randolph Assistant Examiner-Robert T. Bond Attorney-John Kelich and Earl C. Spaeth [57} ABSTRACT ,2-Dihydr0-8-phenyl-3Hpyrido[3,2,1-jk][ l,4]benzodiazepin-5(6H)-0nes, processes for preparing the same and intermediates prepared by said processes; The novel compounds of this invention exhibit tranquilizing and anticonvulsant activity in animals.

2 Claims, N0 Drawings PYRIDOBENZODIAZEPINONES BRIEF SUMMARY OF THE INVENTION 11 1 R l l 9 4 formula wherein R is the same as above and R is selected from the group consisting of hydrogen, acetyl and bromoacetyl.

The novel compounds of the invention can be prepared by the process represented by the following equations:

il g IICl/HzO Step 5 HzN-CHz-COOEt-HCI Step 8 Pyridine I, R j

NIh/MeOH Step 7 CHzBr No I wherein R is the same as above.

DETAILED DESCRIPTION Step 1 of the above process is carried out by treating a solution of the appropriate l,2,3,4-tetrahydroquinoline (III) in dilute aqueous sulfuric acid with an aqueous solution of sodium nitrite. Step 2 is carried out by treating a stirred mixture of the l-nitroso-l,2,3,4- tetrahydroquinoline (IV), methanol and zinc dust with acetic acid to yield V. Step 3 involves refluxing a solution of the l-amino-l,2,3,4-tetrahydroquinoline (V), phenylacetone and acetic acid in benzene with azeotropic distillation of water, concentrating the resulting solution and heating the residue in 2M ethanolic sulfuric acid to yield a 5,6-dihydro-2-methyl- 1-phenyl-4H-pyrrolo-[3,2,l-ij]quinoline (VI). The conditions utilized in these three steps are described in considerable detail by Kost et al., J. Gen. Chem., 29, 1,920 and 3,937 (1959).

In step 4, a stirred mixture of the 5,6-dihydro-2- methyl-l-pheny1-4I-l-pyrrolo[3,2,1-ij]quino1ine (VI), water, dioxane and sodium metaperiodate is kept at 5070AC. for 18-36 hours. The mixture is then poured into water and the product extracted with a suitable organic solvent such as methylene chloride, chloroform or ether to give a l-actyl-B-benzoyl-l ,2',3,4- tetrahydroquinoline (Ila).

In step 5, a mixture of Ila, 6N hydrochloric acid and ethanol is refluxed for 10-24 hours to yield an 8- benzyl-l ,2,3,4-tetrahydroquinoline (IIb).

In step 6, a solution of IIb and an acid acceptor such as pyridine or triethylamine in benzene or ether is treated at ambient temperature with bromoacetyl bromide and allowed to stand for 1-5 hours to give an 8- benzoyl-l-bromoacetyl-l ,2,3,4-tetrahydroquinoline (l- I tion .mixture by conventional procedures such as crystallization, evaporation, chromatography and combinations thereof.

In step 8, a solution of H12 and ethyl glycinate hydrochloride in dry pyridine is refluxed for 8-24 hours. During the first few hours of the reaction the ethanol-water-pyridine azeotrope is slowly distilled from the mixture. The product (I) is recovered from the reaction mixture by conventional procedures such ascrystallization, evaporation, chromatography and combinations thereof.

The acid addition salts of the invention comprise the salts of the compounds of formula (I) and the compounds of formula ll wherein R, is hydrogen with pharmacologically acceptable acids 'such as sulfuric, hydrochloric, nitric, phosphoric, lactic, benzoic, methanesulfonic, p-toluenesulfonic, salicyclic, acetic, propionic, maleic, malic, tartaric, citric, cyclohexanesulfamic, succinic, nicotinic, ascorbic acids, and the like. I

The novel compounds and intermediates of this invention exhibit tranquilizing and anticonvulsant activity. These activities were evaluated by use of the following tests.

CHIMNEYTEST [Med. Exp. 4, ll (19 61)] This test determines the ability of mice to back up and out of a vertical glass cylinder within 30 seconds. Failure of mice to back up and out within this time indicates tranquilization.

DISH TEST Mice in Petri dishes cm. diameter, 5 cm. high, partially embedded in wood shavings) climb out in a very short time, when not treated. Mice remaining in the dish for more than 3 minutes indicates tranquilization.

PEDESTAL TEST Mouse is placed on a pedestal. The untreated mouse leaves the pedestal in less than a minute to climb back to the floor of the. standard mouse box. Tranquilized mice will stay more than 1 minute.

NICOTINE ANTAGONISM TEST novel compounds of this invention (administered intraperitoneally) are set forth in the following table. The results are expressed in terms of the mg./kg. dosage at which the tested compounds exhibited the activity in 50 percent of the mice (ED,,,,).

Compound l i 2 TEST Chimney 200 159 Dish 50 89 Pedestal 142 I42 N.A.*

TE" 12.5 I

N .A.Nicotine Antagonism TE-Tonic Extensor Fits "D-Death For purposes of administration to birds and to mammals, including animals of economic value such as horses, cattle, sheep, pigs, mice, rats, rabbits and the like, the novel compounds of the invention can be combined with solid or liquid pharmaceutical carriers and formulated in the form of tablets, powder packets, capsules and the like solid dosage forms, using starch and like excipients, or dissolved in suitable solvents or vehicles for oral or parenteral administration.

Also, for mammals and birds food premixes, with starch, oatmeal, dried fishmeat, fishmeal, flour and the like can be prepared.

The novel compounds of this invention having the formula (1) and the formula (11) wherein R is hydrogen also form thiocyanic acid addition salts which when condensed with formaldehyde, form resinous materials useful as pickling inhibitors according to US. Pats. Nos. 2,425,320 and 2,606,155. The fluosilicic acid addition salts are useful as mothproofrng agents according to US. Pats. Nos. 1,915,334 and 2,075,359.

The following examples are set forth to illustrate my invention and to enablepersons skilled in the art to better understand and practice the invention and are not intended to limit the same.

Example 1 l-ACETYL-S-BENZOYL-l ,2,3,4- TETRAHYDROQUINOLINE A stirred mixture of 49.4 gm. (0.20 mole) of 5,6- dihydro-2-methyll -phenyl-4H-pyrrolo[ 3 ,2, l ij ]quinoline, 106.5 gm. (0.50 mole) of sodium metaperiodate, 2,000 ml. of dioxane and 570 ml. of water. is heated under a nitrogen atmosphere at 60C. for 20 hours and poured into water. This mixture is extracted with chloroform. The chloroform extract is washed with water, dried over magnesium sulfate and concentrated in vacuo. The residue is chromatographed' on 3.5 kg. of

' 1,2,3,4 tetrahydroquinoline melting point 132-133.5

Anal. Calcd. for C N 'NO C, 77.39; H, 6.13; N, 5.01.

Found: C, 77.47; H, 6.46; N, 4.95. Using the procedure of Example 1, but replacing 5,6- dihydro-Z-methyl- 1 -phenyl-4H-pyrrolo 3 ,2, l -ij ]quinoline by the appropriately substituted 5,6-dihydro-2- 7 methyl- 1 -phenyl-4H-pyrrolo- 3 ,2, l -ij ]quinoline is productive of the corresponding l-acetyl-8-benzoyll,2,3,4-tetrahydroquinoline. Representative of the 1- acetyl-S-benzoyl-l,2,3,4-tetrahydr0quin0lines so ob tained are: Y

l-acetyl-8-benzoyl-6-methyll-acetyl-8-benzoyl-6-ethyl- 1-acetyl-8-benzoyl-6-methoxyl-acetyl-8-benzoyl-6-ethoxy l-acetyl-8-benzoyl-6-chloroand l-acetyl-8-benzoyl-6-bromo-1 ,2,3 ,4-tetrahydroquinoline. Example 2 TETRAHYDROQUINOLINE A stirred mixture of 23.4 gm. (0.0837 mole) of lacetyl-8-benzoyl-1,2,3,4-tetrahydroquinoline (Example 1), 595 ml. of ethanol and 300 ml. of 6N hydrochloric acid is refluxed for hours and allowed to stand at ambient temperature for 18 hours. This mixture is concentrated to about 300 ml. under reduced pressure and poured into water. This solution is cooled in an ice bath, made alkaline with sodium hydroxide and extracted with ether. The ether extract is dried over anhydrous potassium carbonate and concentrated under reduced pressure. The residue is crystallized from petroleum ether to give 17.6 gm. (88.9 percent yield) of crude product. This product is recrystallized from petroleum ether to yield 8-benzoyl-l,2,3,4- tetrahydroquinoline, melting point 68-69.5C.

Anal. Calcd. for C H NO: C, 80.98; H, 6.37; N, 5.90.

Found: C, 81,05; H, 6.77; N, 5.88.

Using the procedure of Example 2, but replacing lacetyl-S-benzoyl-l,2,34-tetrahydroquinoline by the appropriately substituted l-acetyl-S-benzoyl-l,2,3,4- tetrahydroquinoline is productive of the corresponding 8-benzoyl-1,2,3,4 of the S-benzoyl-l,2,3,4-tetrahydroquinolines so obtained are:

8-benzoyl-6 -methyl- 8-benzoyl-6-ethyl- 8-benzoyl-6-methoxy- 8-benzoyl-6-ethoxy- 8benzoyl-6-chloroand 8-benzoyl-6-bromo- 1 ,2 ,3 ,4-tetrahydroquinoline. Example 3 S-BENZOYL- 1 -BROMOACETYL- l ,2,3 ,4- TETRAHYDROQUINOLINE A stirred solution of 1.0 gm. (4.22 millimoles) of 8- benzoyl-l,2,3,4-tetrahydroquinoline (Example 2) and 0.4 ml. of pyridine in 85 ml. of ether is treated with 1.02 gm. (5.06 millimoles) of bromoacetyl bromide and kept at ambient temperature for 2.5 hours. The ether solution is then washed with water, dried over potassium carbonate and concentrated in vacuo. The residue is chromatographed on 100 gm. of silica gel with 40 percent ethyl acetate-60 percent cyclohexane (by volume); 40-ml. fractions are collected. The product, 8-benzoyll -bromoacetyl-1 ,2,3,4- tetrahydroquinoline (0.525 gm. in the form of an oil, is eluted in fractions 5-10.

Using the procedure of Example 3, but replacing 8- benzoyl-l,2,3,4-tetrahydroquinoline by the appropriately substituted 8-benzoyl-1 ,2,3,4- tetrahydroquinoline is productive of the corresponding 8-benzoyl- 1 -bromoacetyll ,2,3,4-tetrahydroquinoline. Representative of the 8-benzoyl-1-bromacetyl-l,2,3,4- tetrahydroquinolines so obtained are:

8-benzoyl-1 -bromacetyl-6-methyl- 8-benzoyl-1 -bromacetyl-6-ethyl- 8-benzoyl-1 -bromoacetyl-6-methoxy- 8-benzoyl-1-bromacetyl-6-ethoxy- S-benzoyl-1-bromacetyl-6-chloroand 8-BENZOYL-1,2,3 ,4-

8-benzoyl- 1 -bromacetyl-6-bromo-l ,2,3 ,4- tetrahydroquininoline.

Example 4 1,2-D1HYDRO-8-PHENYL-31-1-PYR1DO [3 ,2,1-jk][1,4]-BENZODIAZEPlN-5(6H)-ONE Method A A solution of 0.525 gm. of 8-benzoyl-1-bromoacetyll,2,3,4-tetrahydroquinoline in 25 ml. of tetrahydrofuran is treated with 19.9 ml. of methanol saturated with ammonia at ambient temperature. This mixture is stirred for 18 hours and concentrated in vacuo. A suspension of the residue in water is extracted with methylene chloride. The extract is dried over anhydrous potassium carbonate and concentrated in vacuo. Crystallization of the residue gives 0.22 gm. (18.9 percent yield) of crude product. This product is crystallized from ethyl acetate to give 1,2-dihydro-8- phenyl-3H-pyrido[3,2,l-jk][ l ,4lbenzodiazepin- 5(6H)-one, melting point 170.517 1 .5 Anal. C alcdI for c d-1 N 01 C, 78.23; H, 5.84; N, 10.14.

Found: C, 78.21; H, 5.89; N, 10.15.

Using the procedure of Example 4, Method A, but replacing 8-benzoyl- 1 bromoacetyl- 1 ,2,3 ,4- tetrahydroquinoline by the appropriately substituted 8- benzoyll -bromoacetyl-1 ,2 ,3 ,4-tetrahydroquinoline is productive of the corresponding 1,2-dihydro-8-phenyl- 3H-pyrido[3,2,1-jk][ l ,4]benzodiazepin-5(6H)-one. Representative of the 1,2-dihydro-8-phenyl-3H- pyrido[ 3 ,2, l -jk]-[ 1,4]benzodiazepin-5(6H)-ones so obtained are:

l ,2-dihydrol 0-methy1-8-phenyl- 1 ,2-dihydrol O-ethyl-S-phenyll ,2-dihydro- 10-methoxy-8-phenyl- 1 ,2-dihydro-10-ethoxy-8-phenyllO-chloro-l ,2-dihydro-8-phenyll0-fluoro-l,2-dihydro-8-phenyland 10-bromo-1,2-

dihydro-8-phenyl-31-1-pyrid0[3,2,1-jk] 1,4 ]benzodiazepin-5(6H)-one. Method B A mixture of 2.37 gm (0.01 mole) of 8-benzoyl- 1,2,3,4-tetrahydroquinoline (Example 2), 2.79 gm. (0.02 mole) of ethyl glycinate hydrochloride and 20 ml. of pyridine is refluxed under a nitrogen atmosphere for 24 hours. During this period, pyridine is slowly distilled from the mixture; the volume is kept constant by the addition of fresh dry pyridine. The cooled reaction mixture is concentrated in vacuo, and the residue is suspended in water and extracted with ether. The ether extract is washed with water and a saturated solution of sodium chloride, dried over anhydrous magnesium sulfate and concentrated in vacuo. A solution of the residue in ethyl acetate is decolorized by contacting it with decolorizing carbon and the product is crystallized from ethyl acetate-Skellysolve B hexanes to give 1.06 gm. (38.3 percent yield) of 1,2-dihydro-8-phenyl-3H- pyrido[3,2,1-jk][ 1,4]benzodiazepin-5(6H)-one, melting point l72.5C. This material is identical to the material obtained in Method A by infrared, ultraviolet and nmr comparisons.

Representative of the compounds that can be prepared by Method B are the 1,2-dihydro-8-phenyl-3 H-pyrido 3 ,2,1-jk][ l ,4] benzodiazepin-5 6H )-.ones listed in Method A of Example 4.

I claim:

1. A process for preparing a compound having the formula clusive, bromo, chloro and fluoro which comprises 10 QM, i111.

wherein R- is selected from the group consisting of i no hydrogen, alkyl of from one to three carbon atoms, in-i wherein R is the same as above and elusive, alkoxy of from one to three carbon atoms, m-

b. treating 1 with a solution of anhydrous ammonia in 2. A compound having the formula lagjij l5 I I or its addition salts with pharmacologically acceptable acids.

a. reacting a compound having the formula t 2O mide in the presence of an acid acceptor to form a product having the formula p a 

1. A process for preparing a compound having the formula wherein R is selected from the group consisting of hydrogen, alkyl of from one to three carbon atoms, inclusive, alkoxy of from one to three carbon atoms, inclusive, bromo, chloro and fluoro which comprises a. reacting a compound having the formula wherein R is the same as above, with bromoacetyl bromide in the presence of an acid acceptor to form a product having the formula wherein R is the same as above, and b. treating 11c with a solution of anhydrous ammonia in 